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为了深入研究分布式认知无线电网络的多路径路由问题,阐述了分布式认知无线电网络基本特征以及多路径路由设计面临的问题与挑战。分布式认知无线电网络多路径路由采用多路径并行传输,可有效降低传输时延、增加网络吞吐量与传输可靠性、实现网络负载均衡。根据路由优化目标不同,从吞吐量、带宽、干扰、时延、负载均衡和路由发现六方面对近年来多路径路由协议的主要研究成果进行了分类,然后逐类对多路径路由协议进行了分析和讨论,最后分别从分布式认知无线电网络基本特征的适应性与多路径路由协议特征两个方面进行了比较,并展望了分布式认知无线电网络多路径路由协议需进一步研究的方向。 相似文献
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在认知无线电中,网络层用于确定如何在网络中找到一条从源节点到目标节点的路径,且数据路径应当是适应频谱状况的,即尽可能绕过主用户频繁出现的区域。由于频谱是随机的,因而数据路径也可能是随机的。文章分析认知无线电网络中路由面临的挑战,介绍认知无线电网络中的两种路由方案:静态路由和动态路由,给出静态路由频谱选择阶段的5个指标,研究静态路由下一跳选择阶段的优化问题,最后提出认知无线电网络动态路由的实现方案。 相似文献
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认知无线电网络架构与协议体系 总被引:1,自引:0,他引:1
认知无线电网络具有动态、灵活、智能地使用频谱资源,提高频谱利用率的特点,其网络结构和协议体系的设计是实现上述网络功能的关键。现有基于认知无线电技术的网络架构主要有美国的CORVUS系统,基于IEEE 802.22的无线局域网(WRAN)和支持多信道多接口的无线Mesh网络;协议体系有CORVUS协议体系,军用的XG系统协议及WRAN协议等。 相似文献
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随着新型无线业务的不断发展,频谱供需矛盾日益明显.认知无线电网络被认为是实现动态频谱共享、缓解频谱供需矛盾的重要途径,近年来相关研究受到了广泛关注.本文对认知无线电网络中的频谱分配研究进展进行了分析.论文首先介绍了认知无线电网络的技术背景,分析了认知无线电网络中频谱分配的关键问题和算法设计目标.在此基础上总结了主流频谱分配模型的设计思想与技术特点,并详细描述了各模型经典分配算法的实现机制.最后,对频谱分配研究趋势进行了展望. 相似文献
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在SEARCH路由协议中,如果当前路由处于前向避免区域,会造成频谱切换,影响网络拓扑,增加端到端延迟和能量消耗。提出基于地理位置和前向反馈的认知路由算法来解决这一问题。通过信息反馈,该算法能可靠地选择最佳下一跳路由;同时提出认知网络路由算法的评估方案。仿真表明,所提路由选择算法可以很好地降低端到端的延迟和能量消耗。 相似文献
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随着异构网络融合和网络自适应化逐渐成为必然的发展趋势,认知无线网络随之出现,并提供了一种实现全局端到端目标优化的方法。认知无线网络由能自适应改变自身配置的网络设备组合而成,为设计灵活高效的拓扑策略提供了可能性和保障。提出了一种拓扑重构的控制策略,能够规划数据传输路由,在高效利用空闲频谱资源的同时,提升了传输的效率和性能。 相似文献
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Cognitive Radio Networks (CRNs) have been receiving significant research attention recently due to their ability to solve issues associated with spectrum congestion and underutilization. In a CRN, unlicensed users (or Secondary Users, SUs) are able to exploit and use underutilized licensed channels, but they must evacuate the channels if any interference is caused to the licensed users (or Primary Users, PUs) who own the channels. Due to the dynamicity of spectrum availability in CRNs, design of protocols and schemes at different layers of the SU’s network stack has been challenging. In this article, we focus on routing and discuss the challenges and characteristics associated with it. Subsequently, we provide an extensive survey on existing routing schemes in CRNs. Generally speaking, there are three categories of challenges, namely channel-based, host-based, and network-based. The channel-based challenges are associated with the operating environment, the host-based with the SUs, and the network-based with the network-wide SUs. Furthermore, the existing routing schemes in the literature are segregated into three broad categories based on the relationship between PUs and SUs in their investigation, namely intra-system, inter-system, and hybrid-system; and within each category, they are further categorized based on their types, namely Proactive, Reactive, Hybrid, and Adaptive Per-hop. Additionally, we present performance enhancements achieved by the existing routing schemes in CRNs. Finally, we discuss various open issues related to routing in CRNs in order to establish a foundation and to spark new interests in this research area. 相似文献
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Xianwei Zhou Lin Lin Jianping Wang Xuesong Zhang 《Wireless Personal Communications》2009,49(1):123-131
In this paper, the cross-layer design routing in cognitive radio(CR) networks is studied. We propose a colored multigraph
based model for the temporarily available spectrum bands, called spectrum holes in this paper. Based on this colored multigraph
model, a polynomial time algorithm with complexity O(n
2) is also proposed to develop a routing and interface assignment, where n is the number of nodes in a CR network. Our algorithm optimizes the hop number of routing, meanwhile, the adjacent hop interference
(AHI) is also optimized locally.
相似文献
Lin Lin (Corresponding author)Email: |
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Today’s static spectrum allocation policy results in a situation where the available spectrum is being exhausted while many
licensed spectrum bands are under-utilized. To resolve the spectrum exhaustion problem, the cognitive radio wireless network,
termed CogNet in this paper, has recently been proposed to enable unlicensed users to dynamically access the licensed spectrum bands that
are unused in either temporal or spatial domain, through spectrum-agile cognitive radios. The CogNet plays the role of secondary
user in this shared spectrum access framework, and the spectrum bands accessible by CogNets are inherently heterogeneous and
dynamic. To establish the communication infrastructure for a CogNet, the cognitive radio of each CogNet node detects the accessible
spectrum bands and chooses one as its operating frequency, a process termed channel assignment. In this paper we propose a graph-based path-centric channel assignment framework to model multi-hop ad hoc CogNets and perform channel assignment from a network perspective.
Simulation results show that the path-centric channel assignment framework outperforms traditional link-centric approach.
Chunsheng Xin received the Ph.D. degree in computer science from State University of New York at Buffalo in 2002. From 2000 to 2002, he was a Research Co-Op in Nokia Research Center, Boston. From 2002, he is an assistant professor in the Computer Science Department, Norfolk State University, Norfolk, Virginia. His research interests include optical networks, cognitive radio wireless networks, and performance evaluation and modeling. Liangping Ma received his B.S. degree in Physics from Wuhan University, Hubei, China, in 1998, and his Ph.D. degree in Electrical Engineering from the University of Delaware, Newark, DE, in 2004. He was with the University of Delaware as a Postdoctoral Research Fellow. Since 2005, he has been with San Diego Research Center, Inc. (now part of Argon ST, Inc.), San Diego, CA, as a Research Staff Member. His research interests include medium access control (MAC), spectrum agile radios, and signal processing. Chien-Chung Shen received his B.S. and M.S. degrees from National Chiao Tung University, Taiwan, and his Ph.D. degree from UCLA, all in computer science. He was a senior research scientist at Bellcore (now Telcordia) Applied Research working on control and management of broadband networks. He is now an associate professor in the Department of Computer and Information Sciences of the University of Delaware, and a recipient of NSF CAREER Award. His research interests include ad hoc and sensor networks, dynamic spectrum management, control and management of broadband networks, distributed object and peer-to-peer computing, and simulation. He is a member of both ACM and IEEE. 相似文献
Chien-Chung ShenEmail: |
Chunsheng Xin received the Ph.D. degree in computer science from State University of New York at Buffalo in 2002. From 2000 to 2002, he was a Research Co-Op in Nokia Research Center, Boston. From 2002, he is an assistant professor in the Computer Science Department, Norfolk State University, Norfolk, Virginia. His research interests include optical networks, cognitive radio wireless networks, and performance evaluation and modeling. Liangping Ma received his B.S. degree in Physics from Wuhan University, Hubei, China, in 1998, and his Ph.D. degree in Electrical Engineering from the University of Delaware, Newark, DE, in 2004. He was with the University of Delaware as a Postdoctoral Research Fellow. Since 2005, he has been with San Diego Research Center, Inc. (now part of Argon ST, Inc.), San Diego, CA, as a Research Staff Member. His research interests include medium access control (MAC), spectrum agile radios, and signal processing. Chien-Chung Shen received his B.S. and M.S. degrees from National Chiao Tung University, Taiwan, and his Ph.D. degree from UCLA, all in computer science. He was a senior research scientist at Bellcore (now Telcordia) Applied Research working on control and management of broadband networks. He is now an associate professor in the Department of Computer and Information Sciences of the University of Delaware, and a recipient of NSF CAREER Award. His research interests include ad hoc and sensor networks, dynamic spectrum management, control and management of broadband networks, distributed object and peer-to-peer computing, and simulation. He is a member of both ACM and IEEE. 相似文献